Tmobil galaxy on5 has service outside inside it switches to att but no data

[Dan Aitkins]

Hey community net10 offered me a samsung galaxy on5 free. I found out after the fact it was a tmobil phone not att like my previous one an s3mini. I have mobile service outside my house but inside nothing I can use the att network on this phone but only talk n txt no mms or data on the att network everything works on tmobil end except in my home. I hate switching every time I leave n then when I get home. I tried putting in an apn setting for att but the phone dealers it when I enter 410 for the mnc number which is 410 for att 260 for tmobil. Also I cannot use wifi calling because it bumps to att when in my home. The phone is locked to tmobil I'm told please help me?